1. Field of the invention
This invention relates to a semiconductor sensor having a corrugation support member, more specifically, a method of forming the corrugation support is obtained in accordance with a characteristic of a base substrate.
2. Related Art
It is well known that corrugated diaphragms provide advantages over flat diaphragms in utilizing, for example, a pressure transducer. One of the advantages is that the corrugated diaphragm is a more travel distance per unit of applied force.
In conventional art described in U. S. Pat. No. 5,064,165, as shown in FIGS. 8-11, a process for forming corrugated pressure transducers or the like is described. In FIG. 8, a wafer 101 is made of, for example, silicon. First, a top surface 102 of the wafer 101 is masked by depositing either an oxide or a nitride layer 103. In the same manner, second surface 104 is masked at the same time or later by material described above. Thereafter, as shown in FIG. 8, a portion of the layer 103 is removed in the areas where corrugations are to be etched (at the portion 105). The top surface 102 of the silicon material is etched by using a silicon etching gas, such as sulfur hexafluoride. Then, as shown in FIG. 9, profiles 106 is formed in accordance with type of etching process. After that, the layer 103 is removed from the top surface 102. Then, in FIG. 10, an etch stop 107 is diffused into top surface. The etch stop 107 is typically provided by doping surface with an impurity. Thereafter, a mask is formed in the layer 103 formed on the second surface 104. The second surface 104 is then etched to remove the silicon up to the etch stop 66 with corrugations 108 being formed.
However, in this method, in order to form the corrugation, the surface of the wafer is masked by depositing either the oxide or the nitride layer, thereafter, the oxide or nitride layer serving as mask should be removed from the wafer prior to the deposition of the doping surface.